9530127 Hecky This proposal is for a workshop which is intended to overcome major constraints on global change research on inland waters: the need for international cooperation to achieve effective research planning and collaboration on field experiments, the need to conduct thorough and geographically extensive database analyses, and the need to formulate and execute hypothesis-driven comparative studies. The workshop will be structured in order to develop Phase II proposals to the Inter-American Institute for Global Change Research (IAI) in the following themes: effects of hydrologic regimes on biogeochemistry; greenhouse gas flux, mercury cycling and food web performance, UV-dissolved organic carbon interactions and UV effects on aquatic ecosystem structure and function; direct effects of atmospheric chemical changes on aquatic ecosystem structure and function and food web performance; and ecosystem effects of interannual climate variability and effects of El Ni=F1o-Southern Oscillatio= n events. It is anticipated that the Phase II proposals that result from this workshop will extend ongoing activities at the sites to expand the research questions being addressed and to optimize training and education opportunities for international graduate students and researchers, endorse new global change experiments to be conducted at the Canadian sites or elsewhere in the hemisphere, and identify and evaluate the utility of long-term (2 or more ENSO events) data sets, including paleoclimatological data sets which can be analyzed for insight into future ecosystem interactions. There is growing consensus that significant changes are occurring in the earth's atmosphere and that these changes if unabated would lead to significant changes in the earth's ecosystems. The effects of these atmospheric changes in ecosystems are more difficult to detect and can be buried in the complex dynamics that are characteristic of even unstressed ecosystems. The c hallenge that this proposal accepts is to predict the ecosystem and societal consequences of these atmospheric changes and to detect ecosystem changes as early as possible by using the most powerful research approaches available to ecosystem scientists. These approaches are whole system experimentation and time series analysis of ecosystems in relatively remote areas, where they are only responding to the changing atmosphere. %%% This proposal is for a workshop which is intended to overcome major constraints on global change research on inland waters: the need for international cooperation to achieve effective research planning and collaboration on field experiments, the need to conduct thorough and geographically extensive database analyses, and the need to formulate and execute hypothesis-driven comparative studies. The workshop will be structured in order to develop Phase II proposals in the following themes: effects of hydrologic regimes on biogeochemistry; greenhouse gas flux, mercury cycling and food web performance, UV-dissolved organic carbon interactions and UV effects on aquatic ecosystem structure and function; direct effects of atmospheric chemical changes on aquatic ecosystem structure and function and food web performance; and ecosystem effects of interannual climate variability and effects of ENSO events. It is anticipated that the Phase II proposals that result from this workshop will extend ongoing activities at the sites to expand the research questions being addressed and to optimize training and education opportunities for international graduate students and researchers, endorse new global change experiments to be conducted at the Canadian sites or elsewhere in the hemisphere, and identify and evaluate the utility of long-term (2 or more ENSO events) data sets, including paleoclimatological data sets which can be analyzed for insight into future ecosystem interactions. The workshop venues provide ecologically stimulat ing and contrasting environments from both a natural and scientific perspective. The Experimental Lake Area Research Station (ELA) near Kenora, Ontario, is located along a drainage divide at a relatively high elevation. The area abounds with exceptionally deep, extremely oligotrophic, headwater lakes and scattered peatlands with some of the lowest dissolved inorganic carbon concentrations recorded. The area is a wilderness which has resisted settlement by humans and has therefore escaped most of the environmental insults common to lakes and wetland worldwide. These characteristic have made the lakes ideal experimental systems in service to aquatic science as well as insuring that the natural lakes are responding only to global atmospheric changes rather than local impacts. In addition, current global circulation models and linked ecozone models forecast a future as dynamic as the past with serious consequences for these well studied sites and surrounding regions in Central Canada. The known meteorological and geological records of the area indicate a strong positive correlation between air temperature and increasing aridity, and the 25 year integrated ecosystem monitoring at the ELA clearly established that the boreal ecosystems will respond strongly to even short time climatic fluctuation. It has been demonstrated that there is potential to gain from the ELA lakes positive feedback interactions among concurrent changes in atmospheric acidity, UV, and increasing aridity. The following countries are participating in the coordination of this proposal: Canada and the United States. These countries are Members States of the IAI, a U.S. initiative to stimulate cooperative research on global change issues among the scientific institutions of the Americas. The U.S. National Science Foundation is the U.S. Government agency designated to carry out U.S. responsibilities within the IAI. *** --========================_13392204==_--
